Steam and air injector for furnaces



(No Model.)

W. MATHEWS v STEAM AND AIR INJEOIORPORFURNAUES. No. 326,282. 2 PatentedSept. 15, I885.

i /////l I 3 5 @WJTWESSES JJVVEJVTOR UJW ma M4 umm/rw 3 ,4

N. PETERS. Pnclo-umogn her, Wahin mm D. C

UNITED STATES PATENT OFFIcE.

WILLIAM MATHEWS, OF ST. CLAIR, ASSIGNOR OF ONE-HALF TO FRANK A.

HILL, OF PHILADELPHIA, PENNSYLVANIA.

STEAM AND AIR INJECTOR FOR FURNACES.

SPECIFICATION forming part of Letters Patent No. 326,232, datedSeptember 15, 1885. Application filed May 9, 1885. (No model.)

Clair, county of Schuylkill, State of Pennsyl- Vania, have invented anew and useful Improvement in Steam and Air Injectors for Furnaces, &c.,of which the following is a specification.

This improvement relates more particularly to the form of the blower ornozzle passage for the steam, by which more air is entrained and carriedin with the blast than can be done with the ordinary form ofblowernozzles.

The object of the improvement is to simplify the construction of steamair-blast nozzles, to make them positively adjustable, to increase theireffectiveness,and to adapt them to all the purposes for which a steamair-blast is admissible. These objects are attained in the use of thenozzle shown in the accompanying drawings, in which similar lettersindicate similar parts.

Figure 1 represents in perspective the application of the improvement toa nest of horizontal stationary boilers,the wall being partly brokenaway to show the ash-pit and firebars. Fig. 2 represents the blower inlongitudinal section andan end view with the cap removed, a plan of thedetached cap being shown below. Fig. 3 represents in partiallylongitudinal elevation and section, with a top end plan, an alternativemode of construction embodying the same principle of action as in Fig.2.

I am aware that steam air-blast nozzles are not new. See Permanent Way,850., of European Railways, by Oolborn and Holly, 1858, Plate 40, inwhich a steam air-blast arrangement is shown applied to alocomotive-boiler fire-box. My construction of nozzle is different as toform, application, and functional effect.

Nozzles as usually adapted for air-blast purposes are of a conical form,and the steam discharging from the small end of the same will cross andform a reversed cone at a greater or less distance from the aperture ofthe nozzle. According to the angle of the interior of the same, thiscross-intersection of the steam destroys to some extent the force of thecurrent due to the pressure in the boiler, and is to thatextentwasteful. Nozzles of the form described can only be usedeffectively within a reverse-cone blast-pipe, conforming more or lessclosely with the form assumed by the jet, and are wasteful of steam inproportion to the volume of air carried into the ash-pit,combustion-chamber, or stack.

My nozzle is cast of suitable metal for the purpose, having a body, H,neck H, threaded for attachment to a steam-connection, and a center hub,H supported by wings H one or more in number, cast integral therewith,forming an annular space around the hub. Thewings are dropped below theface of the hub, and

inch below the edge of the nozzle bell or body. The inner surface of thebody from the wings to the edge is beveled at an angle-of about fifteendegrees and the hub faced off.

The hub has cast integral with it, or has subsequently attached to it, ascrewed top bolt, I,with anut, I. A disk-cap, J, of the general formshown, has a boss mating the hub of the nozzle, perforated,and threadedat J to fit the bolt I; has a raised exterior boss, J, of a polygonalform for screwing it by a wrench to place, and its periphery beveled atthe same angle as the inner edge of the body, and of 8o such diameterthat when resting upon the hub it shall leave an annular space for theescape of steam of about one sixty-fourthpart of one inch. Should astronger blast be required, the opening is positively adjusted byinterposing washers of copper or suitable material between the cap andhub, and when the desired space has been secured the cap is tightenedand the nut I screwed down,which will retain all in place.

In Fig. 3 I show another form of nozzle, simpler in its construction,but non-adjustable, as the apertures, once determined upon, remain fixedunless it were taken to the shop and the holes separately reamed out,which would of course preclude its subsequent use for a softer blast. Itwill be seen that the body and cap are cast integral with each .the faceof the hub is about one-fourth of an other, and that the outer edge isbeveled at a suitable angle to enable the drill to be operated withoutbreaking, and a series of holes are drilled close to each other, varyingin diameter from one thirty-second to one-fourth of an inch, accordingto the strength of blast desired.

I have found, practically, that for a nest of three boilers, with anaggregate grate-surface of fifty four superficial square feet, anairpipe of about ten inches diameter at the top or outer end, and of sixinches diameter where it passes direct through the wall, or where itrests in a vertical position upon the flanges of a quarter-turn, to passthrough the wall, is of sufficient size. In the latter case, to reducethe friction occasloned by the change in direction of the current, Imake the quarter-turn and its connection through the wall of anincreased diameter-say about ten to twelve inches. The cone-blast orair-pipe I prefer to have about three feet in length,with the aboveproportion of air-pipe to a blowing-nozzle of about two and one-halfinches diameter of body. Culm or the smallest pea anthracite is burnedwithout difiiculty, the combustion being free and the heat intense. Theair-pipe F may be constructed of a uniformdiameter; but I give thepreference to the conical or trumpet form described.

I generally arrange the blower as shown in Fig. 1, taking the steam bypipe E from the front head, A, of the boiler in the steamspaceA,interposing a globe-valve, E, and carrylng the pipe E over the corner ofthe boilerwall to the center of the air-pipe F. From this point, with anelbow and straight 7 length of pipe, E, I drop the blower-nozzle Hcentral to F, and with its annular blowing or et edge about six or eightinches below the top edge of the air-pipe F, the pipe E and connectlonsbeing three-quarter-inch pipe. Steam being turned on, and the supplybeing regulated by the globe-valve E, it passes through the beveledannular edge H, or through the beveled series of holes or jets H and,striking or implnging upon the interior surface of the air-pipe F,closes up its entire area with a stratum or disk of steam, and, as it isdriven forward into the ash-pit, combustion-chamber, or stack, creates apartial vacuum of more or less strength, dependent upon theboilerpressure and the throttling of the globe-valve, and thesurrounding air, rushing into the pipe to balance the same, isintermixed and entrained with the steam, and carried into, say,

the ash-pit D, and, permeating through the bars L and fuel upon thesame, provides the necessary quantity of atmospheric air to keep up alively state of combustion.

This construction of blowing-nozzle is adapted to be used not alone forstationary ter loses, as previously stated, a portion of its vital forcein the cross-currents induced in forming the reverse cone that is tosweep down or through the delivery air-pipe; whereas my improved nozzledelivers the steam at once as a reversed cone, and its action as anair-blower is coincident with the opening of the globevalve, whether thenozzle is within the air-pipe, as shown and described, or placed at suchdistance therefrom as to throw the base of the steam-cone within theair-pipe. B represents the fire-front, O the fire-doors, andD the ashpitdoors.

Having described my invention, shown its use and mode of application,and detailed its advantages, I desire to secure the following claimsthereon:

1. In a combined steam and air injector, the combination of thetrumpet-shaped airpipe F, provided with a delivery-pipe connected to itssmaller end, the steam-nozzle body placed within the said pipe F andprovided with a steam-connection pipe, the central hub, H and wings H,the screwed stud I, projecting from the hub H, the adjustable disk J,adapted to slide loosely upon the stud I, and the nut I, for securingthe disk to the nozzle-body, substantially as described and shown, andfor the purpose set forth.

2. In a combined steam and air injector, the combination of the steamnozzle body adapted to screw on a steam-pipe, and provided with thecentral hub, H and the wings H cast integral with it, the screwed studI, securely fastened into the hub H, the adjustable disk J, adapted toslide loosely upon the stud I, and the nut I, for securing the disk tothe nozzle-body, substantially as described and shown, and for thepurpose set forth.

WILLIAM MATHEWS.

Witnesses:

W. FRED TAYLOR, JNo. DAWSON.

